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Simple CLI to print diffs highlighted with test coverage status

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AdeAttwood/DiffCov

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Diff Cov

Simple CLI to print git and lcov diffs highlighted with test coverage status

Example Output

Installation

You can install the package with npm

npm i -g @adeattwood/diff-cov

You can run it directly with npx

npx @adeattwood/diff-cov

Setup

For diff-cov to get the diff to your default branch, you must set up your origin/HEAD ref. To test to see if you have this set up, run.

git rev-parse --abbrev-ref origin/HEAD

This should print out the origin ref to your default branch for this repo it will print origin/0.x. If you get an unknown ref error, then you will need to link origin/HEAD to your default branch with the below command.

git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/0.x

Note: Make sure you change 0.x for your default branch name typically main or development

Usage

Git diff

Before you run diff-cov you must run your test suite with coverage and output a lcov coverage file. You must also have all your changes committed to ensure it's included in the output.

Once you are ready to go, you can run diff-cov to print your diff highlighted with coverage status. Any line not included in the coverage report will not be highlighted and hit and missed lines will be colored green and red. You can use the --coverageFile flag to specify the path to your coverage report if its not in the default location of ./lcov.info

diff-cov
diff-cov --coverageFile coverage/lcov.info

A report is printed at the bottom and colored with a threshold of 90% anything below this percentage coverage will be colored red.

LCov diff

You can also print the coverage difference between to lcov.info files. To use this run your tests with coverage for a first time. After its finished you can copy your lcov.info file somewhere for later for example:

cp ./lcov.info /tmp/lcov.info

Then you can work on your test and run the tests once more with coverage to generate you a new lcov.info file. Then you can print the difference in coverage between the two files with:

diff-cov --compare /tmp/lcov.info

This can come in handy when you need to find out what a test is testing. You can create your base coverage file, comment out a test, run the tests again and diff the results.